Polypropylenes grafted with an unsaturated monomer bearing an acid anhydride group are known for their adhesive properties which are attributed to the polar groups contributed by this monomer.
It is also known that a restricted concentration of these polar groups is sufficient to impart good adhesive properties to many substrates. Therefore, for reasons of convenience in use, grafted polypropylenes (PPgs) can be diluted in a polyolefin (U.S. Pat. No. 3,856,889). The mixtures have the advantage of the good physical and mechanical properties of the diluent polyolefin and are better in this respect than the PPgs which they contain.
Attempts have been made to increase the adhesive properties of polypropylene grafted with maleic anhydride; thus, with this aim in mind, Japanese Application No. 80/40,396 in 31 Mar. 1980, Publ. No. 81,136,833 claims the addition of an epoxidized fatty acid glyceride to this polymer.